Demonstrated interest

I have a potentially stupid question. I’m seeing s lot of comments that American values demonstrated interest. Over the summer, I traveled to DC to attend Preview Day, and several weeks later I had an interview with an admissions rep near my home town. How is this matched up to my application, or is it?

If you applied using Common App there is a section that allows you to explain how you heard of the university and you can put if you did a campus visit or interview. I did both and indicated it on my Common App

What type of stuff do they like to see that shows you have an interest?